WO2011147892A1

WO2011147892A1 - Use of surface-modified effect pigments in a solvent-free coating agent, solvent-free coating agent and coated object

Info

Publication number: WO2011147892A1
Application number: PCT/EP2011/058593
Authority: WO
Inventors: Michael GRÜNER; Thomas Schneider; Burkhard Schreiber; Günter KAUPP; Ulrich Schmidt; Dirk Schumacher; Christian Wolfrum
Original assignee: Eckart Gmbh
Priority date: 2010-05-26
Filing date: 2011-05-25
Publication date: 2011-12-01
Also published as: DE102010021530A1; EP2576702A1

Abstract

The present invention relates to the use of surface-modified effect pigments in a solvent-free coating agent, the surface-modified effect pigments having a platelet-shaped substrate and at least one dielectric layer, wherein at least one optional protection layer can be disposed on the at least one dielectric layer, and the effect pigments are surface-modified by means of at least one compound containing epoxide groups, under the proviso that the at least one compound containing epoxide groups contains no silicon atoms. The invention also relates to a powder coating material which comprises said surface-modified effect pigments, and to an object coated with a powder coating material comprising said surface-modified effect pigments.

Description

Use of surface-modified effect pigments in a solvent-free coating composition, solvent-free coating composition and coated article

The present invention relates to the use of surface-modified effect pigments in a solvent-free coating composition

solvent-free coating composition containing these surface-modified effect pigments, and a coated article. The surface-modified effect pigments can be used in a powder coating as well as in toners.

Powder coatings are considered to be an ideal solvent-free coating systems with regard to ever stricter environmental regulations, such as VOC guidelines, in many

Applications an alternative to conventional

Wet paint systems. Powder coatings are used, for example, in the painting of vehicle parts, garden furniture, camping articles, household appliances,

Refrigerators or shelves used. For the most part, metallic objects are painted, but painting of e.g.

Plastics or glass. The powder technology is based on the principle of electrostatic charging, whereby the electrostatic charging of the powder coating

usually by the corona process or the triboeiektrische

Procedure is done.

In the corona process, the powder paint is charged via at least one electrode integrated in the powder paint pasteurization. The powder coating passes on the one hand by the conveying air of the powder paint gun and on the other hand by the air movement in the application cabin, caused by the

Extraction, on the substrate to be coated. Supported is the

Deposition by an applied electric field, which also leads to a partial coating of the substrate back. This is called wrap-around. In the triboelectric method, the charge transfer takes place by friction of the powder coating on a teflon tube arranged inside the powder coating gun. Powder coatings applied by this method usually have a positive charge. A combination of the two described methods in the coating process is possible.

Subsequently, the applied powder coating is melted by supplying thermal energy and subsequently cured. Excess powder coating, which does not adhere to the substrate to be coated, can be recycled and reused. Since this so-called overspray is usually finer than the powder coating originally used, the overspray is blended with not yet used powder coating to a stable

Coating process and a high quality

To ensure powder coating.

While the corona process allows a largely universal use of powder coatings, specially adjusted powder coatings are required for the triboelectric process. Powder coatings, which after the Triboelektrischeri methods are applied, generally show on the substrate to be coated better course than after the Corona process applied powder coatings. Without applied external voltage, only a weak electric field builds up, which allows the coating of Faraday cages. Substrates to be coated which have a pronounced cavity are therefore preferably coated by the triboelectric method. The triboelectric method has the further advantage over the corona method that the expense of generating and isolating the high voltage for operating the corona is eliminated. Compared to the corona process, however, the powder coating throughput is lower in the triboelectric process, so that less powder coating per unit time can be applied.

Powder coatings can to achieve different colors and / or optical effects with organic or inorganic colorants and / or

platelet-shaped effect pigments, such as metal effect pigments or

Pearlescent pigments, pigmented.

If powder coating resins are provided, for example, with organic or inorganic pigments, these are combined with others

Powder coating components, such as hardeners, additives or fillers, extruded after mixing and after further process steps for

grinding ready-to-use powder coating. Flake-form effect pigments, such as metal effect pigments or pearlescent pigments, are normally not incorporated into a powder coating in this manner. They are destroyed by the applied shear forces and thus do not give any visual

attractive powder coating.

Alternative methods are available for incorporating platelet-shaped effect pigments into a powder coating. On the one hand the so-called dry blend process, in which platelet-shaped effect pigments and powder coating are mixed. Due to the different shape and chargeability of the Patty-like effect pigments and the powder coating may segregate during application, which makes the reuse of the oversprays difficult or impossible. If the overspray were to be applied again, the resulting powder coating would have altered optical properties. In the corona process is a further disadvantage of powder coatings, which are produced by the dry blend process, the adhesion of effect pigments to electrode and baffle plate

Name powder spray gun. Such agglomerates are entrained from a certain size of the conveying air and lead to hitting on the substrate to be coated to Lackierfehlern, so a

undesirable visual appearance. If the agglomerates get into the overspray, there is an accumulation of the effect pigments, which has an adverse effect on the reuse.

Alternatively, platelet-shaped effect pigments can be incorporated into powder coatings by the so-called bonding method. Here, the powder coating in the presence of piättchenförmigen effect pigments to the

Softening temperature heated and thereby melted on the surface, resulting in a more or less complete physical adhesion of the piättchenförmige effect pigments to the individual powder coating particles. Thus, the segregation occurring during the dry blend process can be avoided.

By means of the powder coating technology, it is possible to apply coating layers with higher layer thicknesses than with conventional coating methods, which may be advantageous in terms of chemical and physical resistance. In addition to the cost-effectiveness of the coating, the layer thickness also influences, for example, the accuracy of fit in the assembly of

powder-coated elements. Surface-coated pearlescent pigments containing phosphorus-containing

Compounds are provided, are described in EP 1 812 518 B1, in powder pigments pigmented with such Perigianzpigmenten show the pearlescent pigments after application a leafing effect. In contrast to powder coatings pigmented with untreated pearlescent pigments, a smaller amount of the pigment covered with the surface can be incorporated

achieve a comparable visual impression of brilliance.

EP 1 339 806 B1 describes a powder coating composition comprising a resin support and a pigment. The pigment is first cast with alumina or a mixture of cerium and

Aluminum oxides and a silane coupling agent coated. The latter can either be applied to the first layer or be present as a mixed layer with this.

From EP 1 646 693 B1, pearlescent pigments suitable for use in powder coatings ("powder coating precursors") are known. These are synthesized according to the periginous pigments described in EP 1 339 806 B1, in which case additionally on the surface of the silane coupling agent, e.g.

Alumina, which is usually added as a giant powder coatings, is present. The silane coupling agent is present as a separate layer.

WO 2006/136435 A2 relates to a method, preferably a

Spray-drying process, for the preparation of periginous pigments, which with a non-cured, chemically crosslinkable and / or under

Exposure to heat, IR radiation, UV radiation and / or

Electron-beam crosslinkable oligomeric and / or polymeric binder are coated. Such pearlescent pigments are characterized by a high flexibility in the application. In Pulveriacken it is particularly advantageous if the coating of the pigment is identical to the Binder of the powder coating is, so that it comes after application and curing of Pulveriacks to form a homogeneous paint layer in which the pearlescent pigments are chemically incorporated. In addition to a pleasing appearance are such paint layers opposite

For example, mechanical loads very stable.

WO 2005/063897 A2 relates to metallic effect pigments prepared by the process according to the teaching of WO 2006/136435 A2.

With a polyglycidyl ether, polyglycidyl ester or

Digiycidylpolysiloxane compound surface-treated pigments are known from EP 0 764 191 B1. This surface treatment is intended to settle and agglomerate the pigments in liquid

Prevent coating agents, such as in a paint or an ink.

Polymer-coated pearlescent and metallic pigments are known from EP 2 098 574 A2. The polymer layer is a prepolymer over a

Coupling reagent covalently bonded to the at least one metal oxide layer of the pigment.

WO 98/46682 A1 describes powder coating compositions which contain metal or pearlescent pigments. To a more even

To ensure chargeability of the pigments and the powder coating, the pigments are treated with a viscous liquid so that the pigments have a sticky surface. After mixing with the powder coating, the powder coating adheres to the sticky surface of the pigments.

US Pat. No. 7,618,489 B2 describes organic or inorganic color pigments coated with an epoxy compound which are used as color filters in flat-panel displays. Object of the present invention is to effect pigments for the

Use in a solvent-free coating composition, in particular a powder coating or a toner to provide, which results in a coating, in particular powder coating or printed image, which has a low optical depth effect.

In the case of the powder coating application of the effect pigments, there should also be no or negligible segregation phenomena at or the electrodes of the powder paint gun.

The effect pigments are intended to be used in a solvent-free

Coating center! allow the provision of a coated article with a visually pleasing appearance without defects in the coating. They are intended for powder coatings in indoor and / or

Be used outdoors. Powder-coated building facades should be distinguished by their good ability to disguise and weather stability. When used as a toner should give a uniform print image.

The problem underlying the invention is achieved by the use of surface-modified effect pigments in a solvent-free

Coating dissolved, wherein the oberfiächenmodifizierte

Effect pigments a platelet-shaped substrate and at least one

have dielectric layer, wherein on the at least one

at least one optional protective layer can be arranged on the dielectric layer, and the effect pigments on the effect pigment surface are surface-modified with at least one epoxide group-containing compound, with the proviso that the at least one epoxide group-containing compound contains no silicon atoms. Preferred developments are specified in the dependent claims 2 to 11.

The object on which the invention is based is also achieved by providing surface-modified effect pigments comprising platelet-shaped substrates with at least one dielectric layer, wherein at least one optional layer is provided on the at least one dielectric layer

Protective layer may be arranged, wherein the effect pigments on the

Effect pigment surface with at least one epoxide group-containing

Compound are surface modified, with the proviso that the

at least one epoxide group-containing compound does not contain silicon atoms, and the surface-modified effect pigments have a specific epoxide equivalent weight ranging from 119,000 to 800, based on the total weight of the surface-modified effect pigments.

The object of the invention is also achieved by providing a

solvent-free coating agent comprising surface-modified effect pigments dissolved, the surface-modified effect pigments having a platelet-shaped substrate and at least one dielectric layer, wherein at least one optional protective layer can be arranged on the at least one dielectric layer, and the effect pigments on the effect pigment surface are surface-modified with at least one epoxide group-containing compound, with the proviso that the

at least one epoxide group-containing compound contains no Siiiziumatome.

Preferred developments of the solvent-free invention

Coating agents are given in claims 14 and 5. Finally, the problem underlying the invention is also achieved by providing a coated article, wherein the

Subject with a solvent-free invention

Coating agent is coated.

These coated with a powder paint objects are preferably facade elements, vehicle parts, bodies,

Household appliances, camping articles, etc.

According to the invention, the at least one epoxide group-containing

Compound no silicon atoms on. Thus, the epoxide group-containing compounds to be used according to the invention do not comprise any

silanes containing epoxide groups and / or siloxanes or polysiloxanes containing epoxide groups. In the following, for reasons of simplification, only compounds containing epoxide compounds are mentioned, but with what

only epoxide compounds containing no (e)

Silicon atom (s) are meant. The invention according to

effect pigments used preferably have no silanes, such as alkyl silanes, as a surface modification.

The inventors have surprisingly found that the

not only according to the invention to be used effect pigments

have performance advantages associated with high quality coatings, i. in particular lead without unwanted pigment agglomerates, but that the visual appearance of the coating is significantly influenced by the inventive modification of the effect pigment surface. Powder coatings comprising the surface-modified effect pigments to be used according to the invention have in the

Difference to, for example, powder coatings containing effect pigments prepared according to WO 2006/136435 A2 or WO 2005/063897 A2 a very homogeneous optical appearance. Containing powder coatings Effect pigments according to WO 2006/136435 A2 or WO 2005/063897 A2 are distinguished by their optical depth and their livelier effect

Appearance.

When the effect pigments according to the invention are used in a toner, an optically finer printed image is obtained.

According to a preferred embodiment of the invention, the solvent-free coating agent is a powder coating or a toner.

The statements made below with regard to the effect pigments to be used according to the invention apply to both

claimed according to the invention effect pigments and the

Coating compositions according to the invention, in particular the

Powder coating according to the invention and the toner according to the invention. Thus, the properties given in the dependent claims 2 to 11 for the effect pigments as well as the explanations below also apply correspondingly to the surface-modified effect pigments claimed in claim 12 and also to the surface-modified effect pigments which are in the solvent-free claimed in claims 13 to 15

Coating agents are included.

A toner is understood to mean a dry toner whose

Solvent content is at most 3 wt .-%, preferably at most 1 wt .-% is. According to a further preferred embodiment, the content of solvent in the dry toner is at most 0.5% by weight. According to another preferred embodiment, the dry toner contains no

Solvents. The data in% by weight relate to the respective

Total weight of the toner. According to a very preferred variant, this is solvent-free

Coating a Pulveriack. The Pulveriack invention preferably contains no solvent.

The invention relates in particular to powder coatings which are prepared by the dry biend process and which contain the surface-modified effect pigments to be used according to the invention.

Suitable platelet-shaped substrates to be coated

surface modified effect pigments are metallic or

non-metallic platelet-shaped substrates.

The metals of the metallic platelet-shaped substrates may be selected from the group consisting of aluminum, copper, zinc, iron, titanium, stainless steel, silver, their alloys, and mixtures thereof.

Preferably, the metals of the metallic platelet-shaped substrates are selected from the group consisting of aluminum, copper, zinc, iron, stainless steel, their alloys and mixtures thereof. The metals of the metallic platelet-shaped substrates are particularly preferably selected from the group consisting of aluminum, copper, zinc, iron, their alloys and mixtures thereof. Most preferably, the metals of the metallic substrates are selected from the group consisting of

Aluminum, copper, zinc, their alloys and their mixtures,

selected. Aluminum platelets are particularly preferably used as metallic platelet-shaped substrates.

The non-metallic platelet-shaped substrates are preferably substantially transparent, preferably transparent, i. for visible light, they are at least partially permeable. Under partially becomes permeable

According to the invention understood that the transmission at least 50%, further preferably at least 70%, more preferably at least 90%, in each case based on the incident light.

The non-metallic platelet-shaped substrates may be selected from the group consisting of natural mica platelets, synthetic

Mica flakes, glass flakes, Si0 ₂ flakes, Al ₂ 0 ₃ platelets,

Polymer platelets, platelet-shaped substrates comprising an inorganic-organic mixed layer are selected. Furthermore, non-metallic platelet-shaped substrates may be glass flakes coated on both sides with semitransparent metal layers selected from the group consisting of silver, aluminum, chromium, nickel, gold, platinum, palladium, copper, zinc, titanium, their alloys, and mixtures thereof , be used. According to the invention, as effect pigments it is also possible to use those whose substrates are mixtures of the platelet-shaped substrates indicated above.

Preferably, the non-metallic platelet-shaped substrates are selected from the group consisting of natural mica platelets, synthetic

Giittel platelets, glass flakes, Si0 ₂ platelets, Al ₂ 0 ₃ platelets and mixtures thereof. Most preferably, the non-metallic platelet-shaped substrates are selected from the group consisting of natural mica platelets, synthetic mica platelets, glass flakes, and mixtures thereof. Very particular preference is given to natural and synthetic mica flakes and their mixtures as substrates.

In particular, natural mica platelets are preferred as the substrate.

The usable as a substrate glass flakes, for example, a

Composition according to the teaching of EP 1 980 594 B1. The surface-modified effect pigments which can be used for the inventive use in solvent-free coating systems, in particular powder coatings, are prepared by forming the platelet-shaped substrates with at least one dielectric

Coating, optionally at least with a protective layer, as well

subsequently provided with at least one epoxide group-containing compound which does not contain silicon atoms.

The at least one dielectric charge, the optionally present at least one protective layer and the surface modification with at least one epoxide group-containing compound can each independently completely envelop the platelet-shaped substrate or be present only partially on the platelet-shaped substrate. The surface-modified effect pigments are preferably distinguished by a uniform, homogeneous structure of each of these layers. Thus, each layer preferably envelops the platelet-shaped substrate or the correspondingly already precoated substrate substantially completely, preferably completely. In particular, preferably also the

Edge areas and not just the top and bottom surfaces of the

platelet-shaped substrates or the corresponding already pre-coated substrates covered.

The at least one dielectric layer of the surface-modified effect pigments is preferably arranged directly on the platelet-shaped substrate. If at least one protective layer is arranged on the at least one dielectric layer, then the protective layer is between the at least one dielectric layer and the second

Surface modification with the at least one epoxide group-containing compound arranged. Since the effect pigment surface is surface-modified with the at least one epoxide group-containing compound, the epoxide group-containing compound is disposed on the outside. The at least one epoxide group-containing compound is preferably present in a layer, preferably at least partially enveloping the effect pigment surface.

In a further embodiment of the invention, the effect pigment to be used according to the invention comprises only a single dielectric layer, which is applied directly to the platelet-shaped substrate. The

Epoxide group-containing compound is in this embodiment directly on the dielectric layer and this at least partially enveloping

applied.

In a further embodiment of the invention, the effect pigment to be used according to the invention comprises only a single dielectric layer, which is applied directly to the platelet-shaped substrate, and a single protective layer, which is applied directly to the dielectric layer. In this embodiment, the epoxide group-containing compound is applied directly to the protective layer and at least partially enveloping it.

In a further variant of the invention, the effect pigment to be used according to the invention has two, three, four, five, six or more

dielectric layers. The dielectric layers are preferably applied directly following one another.

The at least one optional protective layer is preferably disposed externally with respect to the dielectric layers, so that the

dielectric layers are arranged between the platelet-shaped substrate and the protective layer. In a further preferred embodiment, the layer form of dielectric layers is arranged alternately with respect to the refractive index. Preferably, the alternately arranged high and low refractive dielectric layers directly on the substrate, the optional protective layer directly on said Schichtfoige and the epoxide group-containing compound directly on the optional protective layer or directly on said layer sequence are arranged. In a further embodiment, the layer form of alternating high and low refractive dielectric layers preferably starts and ends with a high refractive index layer, so that on the

platelet-shaped substrate, a high refractive index dielectric layer followed by a low refractive dielectric layer followed by a high refractive index dielectric layer.

For the purposes of this invention, a dielectric layer is understood as meaning a coating which is not or slightly electrically conductive, ie a layer having a specific resistance of 1-10 ⁴ ohm and greater. Reference may be made to literature values for known substances.

As the dielectric layer, it is preferable to apply layers comprising metal oxides, metal oxide hydrates, metal hydroxides, metal suboxides,

Metal fluorides, metal oxyhalides, metal chalcogenides, metal nitrides, metal oxynitrides, metal sulphides, metal carbides, organic dielectrics

Materials and / or mixtures thereof include. According to a preferred variant, the dielectric coating consists of the abovementioned materials.

In another embodiment, the dielectric layer may comprise or consist of only a single one of these compounds. alternative For example, the dielectric layer may also comprise several of the compounds listed above in the same layer. For example, the dielectric layer may comprise at least two different metal oxides or a metal oxide and a metal hydroxide of one or more metals. The dielectric layer may thus comprise at least two of the compounds listed above as a mixture in the same layer or as separate layers.

Metal oxides, metal oxide hydrates, metal hydroxides, organic dielectric materials and / or mixtures thereof are preferably used as the dielectric layer. Particular preference is given to using metal oxides and metal oxide hydrates and / or mixtures thereof. Furthermore, it is preferred that the dielectric layer is not an inorganic / organic mixed layer according to DE 10 2006 009 131 A1.

For the purposes of this invention, organic dielectric materials are understood as meaning organic monomers and polymers. These include, inter alia, acrylates, polyethers, polyamides, (poly) urethanes, Polyoiefine, isocyanates, latex or cellulose derivatives. Preferably, acrylates and / or polyethers are used.

The terms layer or coating are used interchangeably within the meaning of this invention, unless stated otherwise.

The dielectric layer may include a high refractive index layer

Refractive index of n 5: 1, 8, preferably of n> 1, 9 and particularly preferably of n> 2.0, or a low refractive index layer with a refractive index on n <1.8, preferably n <1, 7 and particularly preferably of n <1, 6. In a further embodiment, the dielectric layer may be an optically active layer.

As a dielectric high-index layer, for example, are

Metal oxides such as titanium oxide, preferably titanium dioxide (TiO ₂ ), iron oxide, preferably iron (IN) oxide (Fe ₂ O ₃ ), zinc oxide preferably ZnO, tin oxide, preferably tin dioxide (SnO 2), zirconium oxide, preferably

Zirconia (ZrO ₂ ), antimony oxide preferably Sb ₂ O ₃ , magnesium oxide, preferably MgO, cerium oxide, preferably cerium (IV) oxide (CeO ₂ ) and / or cerium (II) oxide (Ce ₂ O ₃ ), cobalt oxide, preferably CoO, chromium oxide,

preferably chromium (IM) oxide (Cr ₂ O ₃ ), copper oxide, preferably copper (I) oxide (Cu ₂ O) and / or copper (II) oxide (CuO), metal sulfides such as zinc sulfide, preferably ZnS, metal oxide hydrates such as goethite (FeOOH ), Titanates such as calcium titanate (CaTi0 ₃ ) or iron titanates such as ilmenite (FeTi0 ₃ ), pseudobrookite (Fe ₂ Ti0 ₅ ) and / or pseudorutile (Fe ₂ Ti ₃ 0 ₉ ) doped

Metal oxides, such as Fe ₂ 0 ₃ doped Ti0 ₂ and / or mixtures thereof.

In a preferred embodiment are called dielectric

high-index layer metal oxides, metal hydroxides and / or

Metal oxide hydrates used. The dielectric high-index layer particularly preferably comprises titanium dioxide, iron (III) oxide, goethite, ilmenite,

Pseudobrookit, pseudorutil and / or their mixtures. Very particularly preferably, the dielectric high-index layer comprises titanium dioxide, iron (III) oxide and / or mixtures thereof. In a further embodiment, the dielectric high-index layer consists of the abovementioned compounds or mixtures thereof.

If the surface-modified effect pigments are coated with titanium dioxide, the titanium dioxide can be modified in the rutile or anatase crystal modification available. Preferably, the titanium dioxide layer is in the rutiiform. The rutile form can be obtained, for example, by applying a layer of tin dioxide to the platelet-shaped substrate to be coated, for example, before application of the titanium dioxide layer. On this layer of tin dioxide, titanium dioxide crystallizes in the rutile modification. The tin dioxide may be present as a separate layer, wherein the layer thickness may be a few nanometers, for example less than 10 nm, more preferably less than 5 nm, even more preferably less than 3 nm. The tin dioxide can also be present at least partially in admixture with the titanium dioxide.

Examples of dielectric low-refraction layers include metal oxides such as silicon oxide, preferably silicon dioxide (S1O2), aluminum oxide, preferably aluminum (III) oxide (Al ₂ O ₃ ), boron oxide, preferably B2O3,

Metailfluoride such as magnesium fluoride, preferably MgF ₂ , aluminum fluoride, preferably AIF ₃ , cerium fluoride, preferably CeF ₃ , calcium fluoride,

preferably CaF ₂ , metal oxide hydrates such as alumina hydrate AIO (OH), silica hydrate, organic monomers and polymers consisting of, for example, acrylates or methacrylates and / or mixtures of the abovementioned compounds.

In a preferred embodiment are called dielectric

low-index layer metal oxides, Metailoxidhydrate and / or organic dielectric materials used. The dielectric low-index layer preferably comprises silicon dioxide, silicon oxide hydrate, aluminum oxide, aluminum oxide hydrate and / or acrylates. In another embodiment, the dielectric low refractive index layer is silicon dioxide,

Aiuminiumoxid, alumina hydrate and / or acrylates. The dielectric low-index layer particularly preferably comprises silicon dioxide and / or silicon oxide hydrate. To increase the light, weather and / or chemical stability, at least one protective layer can furthermore be applied to the at least one dielectric coating. The protective layer can on the one hand

Metal oxides, metal oxide hydrates or metal hydroxides of aluminum, cerium, chromium, silicon, zirconium or mixtures of these metal oxides,

Metal oxide hydrates and / or metal hydroxides include. On the other hand, the protective layer may comprise organic polymers consisting of, for example, acrylates or polyethers.

Preferably, in the case of a non-metallic platelet-shaped substrate, the at least one protective layer comprises metal oxides, metaoxide hydrates and / or metal hydroxides of chromium, cerium and / or silicon. In the case of a metallic platelet-shaped substrate, the at least one protective layer comprises metal oxides, metal oxide hydrates and / or metal hydroxides of silicon and / or organic polymers. In the case of a non-metallic substrate, the at least one protective layer preferably comprises metal oxides, metaoxide hydrates and / or metal hydroxides of chromium, cerium and / or silicon. In the case of a metallic platelet-shaped substrate, the at least one protective layer preferably comprises silicon dioxide, silicon oxide hydrate and / or acrylates. In a further embodiment, the

at least one protective layer of the aforementioned compounds.

In a further embodiment, the at least one protective layer may comprise a single one of the aforementioned compounds. Alternatively, the at least one protective layer may also comprise several of these compounds, which may be present as a mixture or as discrete layers, which preferably follow one another directly. In another embodiment, the protective layer may at least partially form the dielectric layer to form a mixed layer

penetrate.

The surface-modified effect pigments which are suitable for use according to the invention in powder paints have on the

Effect pigment surface, i. on the dielectric layer or the optional protective layer, at least one compound having epoxide groups. Accordingly, mixtures of different epoxide group-containing compounds can also be present.

The epoxide group-containing compound has at least one epoxide group in the molecule. This can be added to saturated or unsaturated, branched or unbranched, substituted or unsubstituted aliphatic or

be bound cycloaliphatic, substituted or unsubstituted aromatic or heterocyclic radicals. For example, the epoxide group may be bonded in the molecule via at least one free carboxylic, sulfonic or phosphonic acid group or at least one free hydroxyl group. The epoxy group-containing compound may have both mono- and di-substituted epoxy groups in the molecule. Under easy

substituted epoxide groups are to be understood as those which carry only one radical other than hydrogen. The of hydrogen

different moieties of the di-substituted epoxy groups can be in both the 1, 1 and 1, 2 positions. In a preferred embodiment, the non-hydrogen radicals of the di-substituted epoxide groups are in the 1, 2-position.

Examples of epoxy group-containing compounds which have a

Epoxy group in the molecule include 1, 2-epoxy-3-methoxypropane (930-37-0), 1, 2-epoxy-3-ethoxypropane (4016-11-9), 1, 2-epoxy-3-propoxypropane (3126-95-2), 1,2-epoxy-3-isopropoxypropane (4016 14-2), 3-butoxy-1,2-epoxypropane (2426-08-6), 3-tert-butoxy-1,2-epoxypropane (7665-72-7), 1, 2-epoxy-3- ( isopentyloxy) propane (15965-97-6), 1,2-epoxy-3- (hexyloxy) propane (5926-90-9), 1,2-epoxy-3- [2- (ethylhexyl) oxypropane (2461-

15-6), 1- (cyclohexyloxy) -2,3-epoxypropane (3681-02-5), 1,2-epoxy-3- (octyloxy) propane (3385-66-8), 1- (decyloxy) - 2,3-epoxypropane (3497-06-1), 4- (2,3-epoxypropoxy) -1-butanol (47 1-95-9), 3- (2,3-epoxypropoxy) -1,2-propanediol (25038-04-4) 4 - [methyl (2,3-epoxypropoxy)!] - 2 _I 2-dimethyl-1, 3- dioxolane (1607-37-0), [(Vinyioxy) methyl 3oxiran (3678! -15-7), 1-allyloxy-2,3-epoxypropane (106-92-3), 2,3-epoxypropyl-propargyl ether (18180-30-8), 1,2-epoxy-3-phenoxypropane (122-60 -1), 1,2-epoxy-3- (2-methylphenyl) propane (2210-79-9), 3- (4-tert-butylphenoxy) -1,2-epoxypropane (3101-60-8), 1 , 2-Epoxy-3- (2-methoxyphenoxy) propane (2210-74-4), 1, 2-epoxy-3- (4-methoxyphenoxy) propane (2211-94-1), 1, 2-epoxy -3- (4-chlorophenoxy) propane (2212-05-7), 3-benzyloxy-1,2-epoxypropane (2930-5-4), 1,2-epoxy-3- (4-vinylbenzyl-oxy) propane (113538-80-0), 2,3-epoxy-1-propyltriphenyl methyl ether (S - (-):

129940-50-7, R - (+): 65291-30-7)), 3- [4- [1- [4- (2,3-epoxypropoxy) phenyl] -1-methylethyl] phenoxy-3-propan-1, 2 -diol (76002-91-0), 2 - [(1-naphthyloxy) methyl] oxirane (2461-42-9), 2- (naphthalen-1-ylmethoxymethyl) oxirane (66931-57-5), 2- [(2,3-epoxypropoxy) methyl] furan (5380-87-0), N- (2,3-epoxypropyl) phthalimide (S - (+): 161596-47-0, R - (-): 181140) -34-1), 4- (2,3-epoxypropoxy) carbazole (51997-51-4), 2,3-epoxypropylacetate (6387-89-9), 2,3-epoxypropylpropionate (37111-25- 4), 2,3-epoxypropyl-n-butyrate (2461-40-7), 2,3-epoxypropyl laurate (1984-77-6), 2,3-epoxypropyl acrylate (106-90-1), 2,3- Epoxypropyl methacryrate (106-91-2), 4- (2,3-epoxypropoxy) butyl acrylate

(119692-59-0), styrene oxide (96-09-3), 3,4-epoxy-1-butadiene (930-22-3), 2,3-epoxy-1-propanol (556-52-5) , 3-oxiranylpropenal (E: 25073-24-9, Z: 25073- 23-8), 1-oxiranylethanone (4401-11-0), 3- (oxiran-2-y-) propyl acetate (59287-65 - 9), methyl 3,4-epoxybutyrate (4509-09-5), 1,2-epoxybutyronitrile (6509-08-6), oxiran-2-ylmethoxyphosphonic acid (23815-70-5), (3-methyloxirane 2-yl) phosphonic acid (23155-02-4), oxiran-2-ylmethyl-4-methylbenzenesulfonate (6746-81-2) or oxiran-2-ylmethyl-3-nitrobenzenesulfonate (R - (-): 115314-17-5).

1,2-Epoxy-3-methoxypropane (930- 37-0), 1,2-epoxy-3-ethoxypropane (4016-11-9), 1, 2-epoxy-3-ethoxypropane (1), 2-epoxy-3-ethoxypropane (1), 2-epoxy-3-propoxypropane (3126-95-2), 1,2-epoxy-3-isopropoxypropane (4016-14-2), 3-tert-butoxy-1,2-epoxypropane (7665-72-7) , 1,2-epoxy-3- (isopentyloxy) propane (15965-97-6),

1.2- Epoxy-3- (hexyloxy) propane (5926-90-9), 1- (cyclohexyloxy) -2,3-epoxypropane (3681-02-5), 1,2-epoxy-3- (octyloxy) propane (3385-66-8), 4- (2,3-epoxypropoxy) -1-butano! (4711-95-9), 3- (2,3-epoxypropoxy) -1,2-propanediol (25038-04-4), 4 - [(2,3-epoxypropoxy) methyl] -2,2-dimethyl 1,3-dioxolane (1607-37-0), [(vinyloxy) methyl] oxirane (3678-15-7), 1-allyloxy-2,3-epoxypropane (106-92-3), 2,3-epoxypropy Propargyl ether (18180-30-8), 1,2-epoxy-3- (2-methoxyphenoxy) propane (2210-74-4), 1,2-epoxy-3- (4-methoxyphenoxy) propane (2211- 94-1), 3-benzyloxy-1,2-epoxypropane (2930-5-4), 1,2-epoxy-3- (4-vinylbenzyloxy) propane (113538-80-0), 3- [4- [ 1- [4- (2,3-epoxypropoxy) phenyl] -1-methylethyl] phenoxy] propane-1,2-diol (76002-91-0), 2,3-epoxypropyl acrylate (106-90-1 ), 4- (2,3-epoxypropoxy) butyl acrylate (119692-59-0),

2.3- Epoxy-1-propanol (556-52-5), 3-oxiranyipropenal (E: 25073-24-9, Z: 25073-23-8), 1-oxiranylethanone (4401-11-0), 3- ( Oxiran-2-yl) propyl acetate (59287-65-9), methyl 3,4-epoxybutyrate (4509-09-5), 1,2-epoxybutyronitrile (6509-08-6), oxiran-2-ylmethoxyphosphonic acid (23815 -70-5), (3-methyl-oxiran-2-yl) phosphonic acid (23155-02-4) and / or mixtures thereof

used.

Particular preference is given to epoxy group-containing compounds which have only one epoxide group in the molecule, 1,2-epoxy-3-methoxypropane (930-37-0), 1,2-epoxy-3-ethoxypropane (4016-11-9), 1 , 2-epoxy-3-propoxypropane (3126-95-2), 1, 2-epoxy-3-isopropoxypropane (4016-14-2), 3-tert- Butoxy-1,2-epoxypropane (7665-72-7), 1- (Cyciohexyloxy) -2,3-epoxypropane (3681-02-5), [(Vinyloxy) methyl] oxirane (3678-15-7), 1 -Allyloxy-2,3-epoxypropane (106-92-3), 2,3-epoxypropyl propargyl ether (18180-30-8), 1,2-epoxy-3- (4-viny1benzyloxy) propane (113538-80- 0), 2,3-epoxypropyl acrylate (106-90-1), 4- (2,3-epoxypropoxy) butyl acrylate (119692-59-0), 3-oxiranylpropenal (E: 25073-24-9, Z: 25073- 23-8), 3- (oxiran-2-yl) propyl acetate (59287-65-9), oxiran-2-yl-methoxyphosphonic acid (23815-70-5) and / or mixtures thereof.

In a preferred embodiment, the epoxide group-containing compound has at least two epoxide groups in the molecule.

In a further embodiment, the epoxide group-containing

Compound two or three epoxide groups in the molecule.

When using an epoxide group-containing compound having at least two or three epoxide groups in the molecule, covalent attachment of the epoxide group-containing compound can take place by reacting an epoxide group with the effect pigment surface, for example a hydroxyl group on the effect pigment surface. The at least one further epoxy group can then in the powder coating a covalent bond with the

Bindieritteikomponente the powder paint enter.

The epoxide group-containing compounds which have at least two epoxide groups in the molecule include, for example, bis (2,3-epoxypropyl) ether (2238-07-5), 1,2-bis (2,3-epoxypropoxy) ethane (2,224- 15-9), 1,4-bis (2,3-epoxypropoxy) butane (2425-79-8), 1,3-bis (2,3-epoxypropoxy) butane (3332-48-7), 1, 5 Bis (2,3-epoxypropoxy) pentane (7517-06-8), 1, 3-bis (2,3-epoxypropoxy) -2,2-dimethylpropane (17557-23-2), 1, 6-bis ( 2,3-epoxypropoxy) - hexane (16096-31-4), 1,2-bis (2 _: 3-epoxypropoxy) cyclohexane (37763-26-1), 1,4-bis [(2,3-epoxypropoxy) methyl] cyclohexane (14228-73-0), 1, 3-bis (oxirane-2) ylmethoxy) propan-2-ol (3568-29-4), bis [2- (2,3-epoxypropoxy) ethyl] ether (4206-61-5), 2,2'-EOxybis [(nriethyl-2,1 -ethandiy!) oxymethylene]] bisoxirane (41638-13-5), PEG-400-DGE (39443-66-8, Raschig), PPG-DGE / PPG-DGE 200 (26142-30-3, 30401- 87-7, Raschig), 1,2,3-tris (2,3-epoxypropoxy) propane (13236-02-7), 1- (2,3-epoxypropoxy) -2,2-bis [(2 , 3-epoxypropoxy) methyl] butane (3454-29-3), 2- [3- [1,3-bis [3- (oxiran-2-ylmethoxy) propoxy] propan-2-yloxy] propoxymethyloxirane (37237- 76-6), 1, 3-bis (2,3-epoxypropoxy) -2,2-bis [(2,3-epoxypropoxy) methyl] propane (3126-63-4), GE 500 (118549-88-5 , 118606-72-7, 16268-64-0, 191548-99-9, Raschig), 1,3-bis (2,3-epoxypropoxy) benzoi (101-90-6), 4,4-bis (2,3-epoxypropoxy) biphenyl (2461-46-3), 2,2-bis [4- (2,3-epoxypropoxy) phenyl] propane (1675-54-3), 2,6-bis (2, 3-epoxypropyl!) Phenyl 2,3-epoxypropyl ether (13561-08-5), 2,2 ', 2 "- [methylidynetris (phenyleneoxymethylene)] trisoxirane (66072-38-6), 2,2', 2" Ethylidyntris (4, 1-phenylene-oxymethylene) trisoxirane (87093-13-8), 1, 1,2,2-Tetrakis [4- (oxiranylmethoxy) phenyl] ethane (7328-97-4), N, N-bis (2,3-epoxypropyl) aniline (2095-06-9), 4- ( 2,3-epoxypropoxy) -N, N-bis (2,3-epoxypropyl) aniline (5026-74-4), 2 _I 4,6-tris (oxiran-2-ylmethoxy) -1, 3,5- triazine (2589-01-7), tris (2,3-epoxypropyl) -1, 3,5-triazine-2,4,6-trione (2451-62-9), bis (oxiran-2-ylmethyl) oxaiate (60468-47-5), bis (2,3-epoxypropyl) malonate (60468-48-6), bis (2,3-epoxypropyl) -2,2-dimethyl-glutarate (25677-88-7), bis (2 , 3-epoxypropyl) adipate (2754-27-0), bis (2,3-epoxycyclohexylmethyi) adipate (3130-19-6), bis (2,3-epoxypropyl) cyclohexane 1,2-dicarboxylate (5493- 45-8), bis (2,3-epoxypropyl) cyclohexene-1,2-dicarboxylate (21544-03-6), bis (2,3-epoxypropyl) phthalate (7195-45-1), bis (2, 3-epoxypropyl) terephthalate (7195-44-0), tris (2,3-epoxypropyl) trimethylate (7237-83-4), 2-methyl-2,2'-bioxirane (6341-85-1 )

1, 2,5,6-Diepoxyhexane (1888-89-7), 1, 2,7,8-Diepoxyoctane (2426-07-5), 1, 2,8,9-Diepoxynonane (24829-11-6) , 1,2,9,10-diepoxydecane (24854-67-9), m-bis (epoxyethyl) benzoi (16832-59-0), bis (2,3-epoxycyclopentyl) ether (2386-90-5) , N, N-bis (2,3-epoxypropyl) cyclohexylamine (13391-15-6), N, N-bis (2,3-epoxypropyl) isopropylamine (19115-57-2), (3, 4-Epoxycyclohexy [) methyl-3,4 ~ epoxy- cyclohexylcarboxylate (2386-87-0) and / or tris (2,3-epoxypropyl) phosphate (18795-33-0).

Preference is given as epoxide-containing compounds which

have at least two epoxide groups in the molecule, bis (2,3-epoxypropyl) ether (2238-07-5), 1,2-bis (2,3-epoxypropoxy) ethane (2224-15-9), 1, 4- Bis (2,3-epoxypropoxy) butane (2425-79-8), 1,3-bis (2,3-epoxypropoxy) butane (3332-48-7), 1,5-bis (2,3-epoxypropoxy) pentane (7517-06-8), 1, 3-bis (2,3-epoxypropoxy) -

2,2-dimethylpropane (17557-23-2), 1,6-bis (2,3-epoxypropoxy) hexane (16096- 31-4), 1,2-bis (2,3-epoxypropoxy) cyclohexane (37763-26- 1), 1,4-bis [(2,3-epoxypropoxy) methyl] cyclohexane (14228-73-0), 1, 3-bis (oxiran-2-ylmethoxy) -propan-2-ol (3568-29- 4), bis [2- (2,3-epoxypropoxy) ethyl] ether (4206-61-5), 2,2 ^, - [oxybis [(methyl-2,1-ethanediyl) oxymethylene]] bisoxirane (41638-13 -5), 1, 2,3-tris (2,3-epoxypropoxy) propane (13236-02-7), 1- (2,3-epoxypropoxy) -2,2-bis- [(2,3-epoxypropoxy ) methyl] butane (3454-29-3), 2- [3- [1,3-bis [3- (oxiran-2-ylmethoxyl) propoxy] propan-2-yloxy] propoxymethyloxirane (37237-76-6), 1,3-bis (2,3-epoxypropoxy) -2,2-bis [(2,3-epoxypropoxy) methyl] propane (3126-63-4),

1,3-bis (2,3-epoxypropoxy) benzene (101-90-6), 4,4'-bis (2,3-epoxypropoxy) biphenyl (2461-46-3), 2,2-bis [4- (2,3-epoxypropoxy) phenyl] propane (1675-54-3), 2,6-bis (2,3-epoxypropyl) phenyl-2,3-epoxypropyl ether (13561-08-5), 2,2 ', 2 "- [Methylidynetris (phenyleneoxymethylene)] trisoxirane (66072-38-6), 2,2 ', 2" - [ethylidynetris (4,1-phenyleneoxymethylene)] trisoxirane (87093-13-8), 1, 1, 2 , 2- Tetrakis [4- (oxiranylmethoxy) phenyl] ethane (7328-97-4), N, N-bis (2,3-epoxypropyl) aniline (2095-06-9), 4- (2,3 -Epoxypropoxy) -N, N-bis (2,3-epoxypropyl) -aniline (5026-74-4), tris (2,3-epoxypropyl) -1, 3 _! 5-triazine-2,4,6-trione (2451-62-9), bis (oxiran-2-ylmethyl) oxalate (60468-47-5), bis (2,3-epoxypropyl) malonate (60468-48- 6), bis (2,3-epoxypropyl) -2,2-dimethylglutarate (25677-88-7), bis (2,3-epoxypropyl) adipate (2754-27-0), bis (2,3-epoxycyclohexylmethyl) adipate (3130-19-6), bis (2,3-epoxypropyl) cyclohexane 1,2-dicarboxylate (5493-45-8), bis (2,3-epoxypropyl) cyclohexene 1,2-dicarboxylate (21544 -03-6), bis (2,3-epoxypropyl) - phthalate (7195-45-1), 2-methyl-2,2'-bioxirane (6341-85-1), 1, 2,5,6-diepoxyhexane (1888-89-7), 1,2, 7,8-Diepoxyoctane (2426-07-5), 1, 2,8,9-Diepoxynonane (24829-11-6), 1, 2,9,10-Diepoxydecane (24854-67-9), m-bis (epoxyethyl) benzoi (16832-59-0), bis (2,3-epoxycyclopentyl) ether (2386-90-5), N, N-bis (2,3-epoxypropyl) cyclohexylamine (13391-15-6), N, N-bis (2,3-epoxypropyl) -isopropylamine (19115-57-2), (3,4-epoxycyclohexyl) methyl-3,4-epoxycyclohexylcarboxylate (2386-87-0) and / or tris ( 2,3-epoxypropyl) phosphate (18795- 33-0) used.

Particular preference is given to epoxide group-containing compounds which have at least two epoxide groups in the molecule, bis (2,3-epoxypropyl) ether (2238-07-5), 1,3-bis (2,3-epoxypropoxy) butane (3332-48 -7), 1,5-bis (2,3-epoxypropoxy) pentane (7517-06-8), 1,2-bis (2,3-epoxypropoxy) cyclohexane (37763-26-1), 1, 3 Bis (oxiran-2-ylmethoxy) propan-2-ol (3568-29-4), bis [2- (2,3-epoxypropoxy) ethyl] ether (4206-61-5), 2,2 '- [oxybis [(methyl-2,1-ethanediyl) oxymethylene]] bisoxirane (41638-13-5), 1,2,3-tris (2,3-epoxypropoxy) propane (13236-02-7), 2- [3 - [1,3-bis [3- (oxiran-2-ylmethoxyl) propoxy] propan-2-yloxy] propoxymethyioxirane (37237-76-6), 2,6-bis (2,3-epoxypropyl) phenyl-2 , 3-epoxypropyl ether (13561-08-5), 2,2 ', 2 "- [ethylidene-thyssen- (phenoxy enoxymethylene)] trisoxirane (66072-38-6), 2,2', 2" - Ethylidyntris (4,1-phenyleneoxymethylene) trisoxirane (87093-13-8), 1,1,2,2-tetrakis [4- (oxiranylmethoxy) phenyl] ethane (7328-97-4), bis ( oxiran-2-ylmethyl) oxalate (60468-47-5), bis (2,3-epoxypropyl) malonate (60468-48-6), Bis (2,3-epoxypropyl) -2,2-dimethyl [glutarate (25677-88-7), bis (2,3-epoxycyclohexylmethyl) adipate (3130-19-6), bis (2,3-epoxypropyl) cyclohexene 1, 2-dicarboxylate (21544-03-6), 2-methyl-2,2'-bioxirane (6341-85-1), 1, 2,5,6-diepoxyhexane (1888-89-7), 1 , 2,7,8-diepoxyoctane (2426-07-5), 1,2,8,9-diepoxynonane (24829-11-6), 1,2,9,10-diepoxydecane (24854-67-9), (3,4-epoxycyclohexyl) methyl-3,4-epoxycyclohexylcarboxylate (2386-87-0), tris (2,3-epoxypropyl) phosphate (18795-33-0) and / or mixtures thereof. Very particular preference is given to epoxide group-containing compounds which have at least two epoxide groups in the molecule, bis (2,3-epoxypropyl) ether (2238-07-5), 1,3-bis (2,3-epoxypropoxy) butane (3332-48 -7), 1, 5-bis (2,3-epoxypropoxy) pentane (7517-06-8), 1,2,3-tris (2,3-epoxypropoxy) propane (13236-02-7), 2 , 6-bis (2,3-epoxypropyl) phenyl-2,3-epoxypropyl ether (13561-08-5), bis (oxirane-2-ylmethyl) oxalate (60468-47-5), bis (2,3-epoxy pyrolylmonate (60468-48-6), bis (2,3-epoxypropyl) -2,2-dimethylmuthate (25677-88-7), bis (2,3-epoxycyclohexylmethyi) adipate ( 3130-19-6), 2-methyl-2,2'-bioxirane (6341-85-1), 1, 2,5,6-diepoxyhexane (1888-89-7), 1, 2,7,8- Diepoxyoctane (2426-07-5), (3,4-epoxycyclohexyl) methyl-3,4-epoxycyclohexylcarboxylate (2386-87-0), tris (2,3-epoxypropyl) phosphate (18795-33-0) and / or mixtures used.

Especially preferred are epoxide groups

Compounds having at least two epoxide groups in the molecule, bis (2,3-epoxypropyl) ether (2238-07-5), 1,3-bis (2,3-epoxypropoxy) butane (3332-48-7), 1, 2,3-Τπ5 (2,3-βροχνρΓοροχν) ρΓορ3η (13236-02-7), 2,6-bis (2,3-epoxypropyl) phenyl-2,3-epoxypropyl ether (13561-08-5), bis ( oxiran-2-ylmethyl) oxalate (60468-47-5), bis (2,3-epoxypropyl) malonate (60468-48-6), bis (2,3-epoxycyclohexylmethyl) adipate (3130-19-6), 1 , 2,5,6-Diepoxyhexan (1888-89-7), tris (2,3-epoxypropyl) phosphate (18795-33-0) and / or mixtures thereof.

The information in brackets refers to the associated CAS numbers.

According to a further embodiment, a mixture of different epoxide group-containing compounds is applied to the Effektpigmentoberfiäche. In this case, for example, one or more epoxidgruppen- containing compound (eri) having only one epoxide group with one or more epoxide group-containing compound (s) having at least two epoxy groups applied together on the effect pigment surface.

According to the invention, the starting material used

epoxide group-containing compound no silane-functional group.

Pigments which are surface-modified with epoxide group-containing compounds having in addition to the epoxide group at least one silane-functional group in the molecule are not compatible with the surrounding powder coating for reasons not yet understood.

This manifests itself in strong adhesion of these pigments on the baffle plate and on the electrode of the powder paint gun, resulting in segregation of

Pigment and powder coating leads. Occurring painting defects in the form of

Pigment agglomerates on the substrate to be coated and a concomitant, insufficient recyclability of overspray are the result. Furthermore, powder coatings which contain such surface-modified effect pigments contain an insufficient coating of the substrate edges during application, which leads to an increased

Susceptible to corrosion.

The epoxide group-containing compound can be applied to the dielectric layer or the optional protective layer by the at least one epoxide group-containing compound with the respective

Effect pigment is optionally mixed in the presence of a solvent and then dried. In this case, 10% by weight, based on the total weight of the surface-modified effect pigment, of at least one compound containing epoxide groups is applied to the dielectric layer or the optionally present protective layer. Preferably, the amount of the at least one epoxy group-containing compound used is in a range of 0.5 to 8 wt%, more preferably in a range from 0.6 to 6 wt .-%, particularly preferably in a range of 0.7 to 5 wt .-% and most preferably in a range of 0.8 to 4% by weight, each based on the total weight of surface-modified effect pigments.

The epoxide group-containing compound is not applied to the dielectric layer or the optional protective layer by the spray-drying method. The spray-drying process is described in WO 2006/136435 A2 or in WO 2005/063897 A2.

The epoxide group-containing compound can have at least one

Epoxy group bound to the dielectric layer or the optional protective layer. According to the invention, it is preferred that at least part of the epoxide groups of the at least one epoxide group-containing compound remain on the effect pigment surface in order to allow a reaction with the powder coating components. Each free epoxide group can be used for further crosslinking of the epoxide group-containing

Compounds serve each other and / or for reaction with the binder component of the powder coating.

The at least one epoxide group-containing compound is preferably applied directly to the pigment surface, i. without coupling reagent applied. The pigments to be used according to the invention therefore have a surprisingly simple structure.

Preferably, the epoxide group-containing compounds have a

Epoxy equivalent weight in the range of 10 to 20,000. Preferably, the epoxy group-containing compounds have a Epoxidäquivalientgewicht in the range of 15 to 15,000 and more preferably in the range of 20 to 10,000. Most particularly preferred exhibit the epoxide group-containing compounds an epoxide equivalent weight ranging from 22 to 7,000 or from 30 to 800.

The epoxide equivalent weight is understood to mean that amount of epoxide group-containing compound in grams which contains 16 grams of epoxide-bonded oxygen (epoxide oxygen).

The determination is carried out, as known to those skilled in the art, by titration with cetyltrimethylammonium bromide under acidic conditions.

The effect pigments surface-modified with an epoxide group-containing compound have a specific epoxide equivalent weight in a range from 119,000 to 800, preferably from a range from 115,000 to 900, and more preferably from a range from 114,000 to 1,000. With very particular preference the surface-modified effect pigments have a specific epoxide equivalent weight in the range from 106,000 to 2,500.

The specific epoxide equivalent weight is understood to mean the amount of pigment in grams which contains 16 grams of epoxide oxygen (epoxide oxygen).

The larger the numerical value of the specific epoxide equivalent weight, the lower the number of free epoxide groups on the effect pigment surface. This has the consequence that fewer free epoxide groups for

Networking with the surrounding binder of the powder coating are available.

The determination of the specific epoxide equivalent weight is carried out in accordance with the determination of the epoxide equivalent weight of the compound containing epoxide groups by titration. This must additionally the Amine number of nicht oberfiächenmodifizierten effect pigment can be determined.

The average diameter of the effect pigments, indicated as D _{50 of} the surface-modified effect pigments, is preferably in a range from 2.0 μm to 100 μm, preferably in a range from 2.5 μm to 75 μm, more preferably in a range of 3.0 μιη to 50 μηι, more preferably in a range of 3.5 μιη to 35 μιη and most preferably in a range of 4.2 to 24 μιτι.

The Dgo value of the diameter of the effect pigments is preferably in a range from 8 to 290 μηη, more preferably in a range from 10 to 240 μιη, even more preferably in a range from 19 to 155 μιη, more preferably in a range of 24 to 90 μιη and most preferably in a range of 16 to 47 μηη.

In the above information, preferably correlate

Area information of D50 and D ₉₀ values in the respectively indicated

Order with each other, i. the first values, the second values, the third values and the fourth values, respectively.

The D ₁₀ , D ₅₀ or Dgo value of the cumulative frequency distribution of

Volume-average size distribution function, as obtained by laser diffraction methods, indicates that 10%, 50%, and 90%, respectively, of the surface-modified effect pigments have a diameter equal to or less than the specified value. In this case, the size distribution curve of the effect pigments based on non-metallic, platelet-shaped substrates is measured using a device from Malvern (device:

MALVERN Mastersizer 2000) and the size distribution curve of the effect pigments based on metallic platelet-shaped substrates a device of the company. Quantachrome (device: Cilas 1064), in each case determined according to the manufacturer's instructions. The evaluation of the scattered light signal was carried out according to the Fraunhofer method.

In a further embodiment, the present invention comprises the use of surface-modified pearlescent pigments in a powder coating, wherein the surface-modified pearlescent pigments based on a platelet-shaped transparent substrate comprise at least one dielectric layer, optionally at least one protective layer, and a surface modification with at least one epoxide group-containing compound.

In a further embodiment, the present invention comprises the use of surface-modified pearlescent pigments in a powder coating, wherein the surface-modified pearlescent pigments based on a platelet-shaped transparent substrate comprise at least one optically active layer, optionally at least one protective layer, and a

Surface modification with at least one epoxide group-containing

Include connection.

In a further embodiment, the present invention comprises the use of surface-modified pearlescent pigments in a powder coating, wherein the surface-modified pearlescent pigments based on flake-form natural or synthetic mica comprise at least one dielectric layer consisting of metal oxides and / or metal oxide hydrates, optionally at least one protective layer, and a

Surface modification with at least one epoxide group-containing

Compound containing no Siiiziumatome in the molecule include. In a further embodiment, the present invention comprises the use of surface-modified pearl pigments in a powder coating, wherein the surface-modified pearlescent pigments based on flake-form natural or synthetic mica comprise at least one dielectric layer, optionally at least one protective layer consisting of metal oxides and / or metal hydroxides, and a surface modification comprising at least one epoxide group-containing compound having at least two epoxide groups.

In a further embodiment, the present invention comprises the use of surface-modified pearlescent pigments in a powder coating, wherein the surface-modified pearlescent pigments based on flake-form natural or synthetic mica comprise at least one dielectric layer consisting of metal oxides and / or metal hydroxides, optionally at least one protective layer consisting of metal oxides,

Metal oxide hydrates and / or metal hydroxides, as well as a surface modification with at least one epoxide group-containing compound having at least two epoxide groups, without silicon atoms in the molecule include.

In a further embodiment, the present invention comprises the use of surface-modified pearlescent pigments in a powder coating, wherein the surface-modified pearlescent pigments based on a platelet-shaped substrate comprise at least one dielectric layer, optionally at least one protective layer, and a surface modification with at least one epoxide group-containing compound, and wherein the surface-modified pearlescent pigments specific epoxide equivalent weight ranging from 119,000 to 800.

In a further embodiment, the present invention comprises the use of surface-modified pearlescent pigments in a powder coating, wherein the surface-modified pearlite pigments based on glass flakes comprise at least one dielectric layer, optionally at least one protective layer, and a surface modification with at least one epoxide group-containing compound.

In a further embodiment, the present invention comprises the use of surface-modified pearlite pigments in a powder coating, wherein the surface-modified pearlite pigments based on glass flakes comprise at least one dielectric layer, optionally at least one protective layer consisting of metal oxides, metal oxide hydrates and / or metal hydroxides, and a surface modification with at least one epoxy group-containing Compound with at least two epoxide groups.

In a further embodiment, the present invention comprises the use of surface-modified metallic effect pigments in one

Powder coating, wherein the surface-modified metallic effect pigments based on a platelet-shaped substrate comprise at least one dielectric layer, optionally at least one protective layer, as well as a surface modification with at least one epoxide group-containing compound.

Powder coating, wherein the surface-modified metallic effect pigments based on a platelet-shaped substrate comprise at least one dielectric layer, optionally at least one protective layer, and a surface modification with at least one epoxide group-containing compound having at least two epoxide groups. In a further embodiment, the present invention comprises the use of surface-modified metallic effect pigments in one

Powder coating, wherein the surface-modified metallic effect pigments based on piättigenförmigem aluminum comprise at least one dielectric layer, optionally at least one protective layer, and an outer layer having at least one epoxide group-containing compound.

Powder coating, wherein the surface-modified metallic effect pigments based on piatal aluminum comprise at least one dielectric layer, optionally at least one protective layer, as well as a surface modification with at least one epoxide group-containing compound having at least two epoxide groups.

Powder coating, wherein the surface-modified metallic effect pigments based on piatal aluminum at least one dielectric layer, consisting of an acrylic, optionally at least one

Protective layer, as well as a surface modification with at least one epoxide group-containing compound.

Powder coating, wherein the surface-modified metallic effect pigments based on piättigenförmigem aluminum at least one dielectric layer consisting of Stiiziumdioxid and / or Siliziumoxidhydrat, optionally at least one protective layer consisting of an acrylic, and a surface modification with at least one epoxy group-containing Compound having at least two epoxy groups, which contains no Siüziumatome in the molecule include.

In a further embodiment, the present invention comprises the use of surface-modified metal effect pigments in one

Powder paint, wherein the based on platelet-copper

surface-modified metal effect pigments comprise at least one dielectric layer, optionally at least one protective layer, as well as a surface modification with at least one epoxide group-containing compound.

Powder coating, wherein the platelet-shaped copper-based surface-modified metal effect pigments comprise at least one dielectric layer, optionally at least one protective layer, as well as a surface modification with at least one epoxide group-containing compound having at least two epoxide groups.

Powder coating, wherein the surface-modified metal effect pigments based on a platelet-shaped substrate comprise at least one dielectric layer, optionally at least one protective layer, as well as a surface modification with at least one epoxide group-containing compound and wherein the surface-modified metal effect pigments have a specific epoxide equivalent weight in the range from 99,000 to 800. In a further embodiment, the present invention comprises a powder-coated article comprising a powdered lacquer comprising surface-modified effect pigments having a specific epoxide equivalent weight in the range from 119,000 to 800.

In a further embodiment, the present invention comprises surface-modified effect pigments based on a platelet-shaped substrate which is coated with at least one dielectric layer, optionally at least one protective layer, and a surface modification with at least one epoxide group-containing compound having an epoxide equivalent weight in the range from 10 to 20,000 ,

In a further embodiment, the present invention comprises surface-modified pearlescent pigments based on natural or synthetic mica, which is coated with at least one dielectric layer, optionally at least one protective layer, and a surface modification with at least one epoxide group-containing compound having an epoxide equivalent weight in the range from 10 to 20,000.

In a further embodiment, the present invention comprises surface-modified metallic effect pigments based on platelet-shaped aluminum, which is coated with at least one dielectric layer, optionally at least one protective layer, and with surface modification with at least one epoxide group-containing compound having an epoxide equivalent weight in the range from 10 to 20,000.

Powder coatings can be used to achieve special color effects in addition to

described surface-modified effect pigments and organic and / or inorganic color pigments and / or colorants and / or further effect pigments.

The described surface-modified effect pigments are particularly suitable for the pigmentation of powder coatings, which are produced by the dry blend process. The segregation of effect pigment and powder coating, which is frequently observed here during application, can be largely avoided by using the surface-modified effect pigments described. If the surface-modified effect pigments to be used according to the invention are mixed with a powder coating by the dry blend method and then applied by the corona method, it is possible to almost completely prevent adhesion of the effect pigments to the electrode (s) and impact plate of the powder coating gun. In particular, there is practically no adhesion at least over a period of 20 s at 100 kV and 100 μΑ application voltage.

If it comes to pigment attachments, these grow with time and are then entrained with the conveying air. On the one hand, this can lead to varnish defects in the form of e.g. Pigment agglomerates and on the other in the overspray lead to a pigment enrichment, which would result in color and / or effect shifts in a reuse of the overspray. By the use of the surface-modified effect pigments to be used according to the invention, powder coatings without coating defects, which are produced by the

caused adhesions are obtained. In addition to the described Lackierfehlern can also powder coatings

occurring black, microscopic defects, so-called "black spots", by the use of the invention to be used

surface-modified effect pigments are bypassed. Of course, the invention to be used

surface-modified effect pigments are also used in powder coatings which are produced by the bonding process.

Powder coatings which contain the surface-modified effect pigments to be used according to the invention are distinguished by the fact that they lead to a good coating of the edges in the baked state after the coating process. An edge escape can thus not be observed.

Furthermore, good fluidizability of the powder coating according to the invention, which contain these surface-modified effect pigments, is given.

The pigmentation of the powder coatings according to the invention with the

Surface-modified effect pigments to be used according to the invention are present at 10% by weight, preferably in a range from 0.5 to <8.0% by weight, more preferably in a range from 0.7 to <6% by weight and very particularly preferably in a range from 1, 0 to -5 wt .-%, each based on the total weight of the pigmented powder coating.

In addition to the above-mentioned surface-modified effect pigments, the inventive powder finishes can additionally be

Charge control additives and / or trickle agents, e.g. pyrolytically produced alumina or pyrolytically produced silicon dioxide are added. These can positively influence the flow behavior of the powder paint.

Powder coatings containing surface-modified effect pigments may be suitable not only indoors but also for outdoor applications. Surface-modified effect pigments used in powder coatings for outdoor use should contain a weather-stabilized effect pigment precursor such as the commercially available Phoenix XT series, the Phoenix CFE series, the Symic OEM series or even the LUXAN CFX series from Eckart GmbH.

The weather-stable effect pigment precursors can be prepared, for example, analogously to EP 1 682 622 B1 and are distinguished by excellent UV and weather stability.

An important criterion in addition to the weather resistance is the

Cleanability of powder-coated building façades (Hans Pfeifer, Journal für Oberflächentechnik 01/2003, p. 24-27). To check the

Facade cleaning ability, for example, a hand cleaning method can be used. For this purpose, a square tube with a soft cloth, which contains a cleaning solution wrapped. This square tube is moved back and forth on the painted object to be checked without pressure. The result is then visually appraised. Powder coatings containing the surface-modified effect pigments to be used according to the invention are distinguished by improved cleanability compared to the corresponding ones

Effect pigments without the described surface modification.

Furthermore, the surface-modified effect pigments can also be used in other solvent-free coating compositions, in particular in toners. The invention thus also relates to toners which contain the surface-modified effect pigments. The invention also includes articles which are printed with a toner containing the surface-modified effect pigments. Articles printed with the toner according to the invention are, for example, printed paper, cardboard or films. In a further embodiment, the present invention relates to the use of surface-modified effect pigments in toners, wherein the surface-modified effect pigments based on a platelet-shaped substrate comprise a dielectric layer, optionally at least one

In a further embodiment, the present invention relates to the use of surface-modified effect pigments in toners, wherein the surface-modified effect pigments based on a platelet-shaped substrate comprise a dielectric layer, optionally at least one

Protective layer, as well as a surface modification with at least one epoxide group-containing compound having at least two epoxy groups.

In a further embodiment, the present invention relates to a toner containing surface-modified effect pigments, wherein the surface-modified effect pigments based on a platelet-shaped substrate comprise a dielectric layer, optionally at least one

Protective layer, as well as an outer layer with at least one

epoxide group-containing compound.

Protective layer, as well as a surface modification with at least one epoxide group-containing compound having at least two epoxy groups. In the following, the invention will be described in more detail by means of examples without wishing to be limited thereto. The surface-modified effect pigments were used in various commercially available powder coatings.

I. Surface-modified effect pigments for use in

powder coatings

Inventive Example 1:

150 g of commercially available weather-stabilized silver pearlescent pigment based on natural mica flakes (Phoenix XT 3001, Eckart GmbH) were presented in a laboratory kneader from IKA. In parallel, 3.1 g of epoxy group-containing compound (Cyracure 6110, Dow Corning, epoxide equivalent weight 131 to 143) were dissolved in 60 g of ethanol having an H ₂ 0 content of 25 wt .-% and then mixed with the pigment in the kneader.

After a mixing time of 20 minutes, the mixture was dried at 120.degree. The resulting surface-modified effect pigment with a

specific epoxide equivalent weight of 118,000 served as

Starting material for the subsequent powder coating applications.

Inventive Example 2:

150 g of commercially available silver pearlite pigment based on natural mica flakes (Phoenix PX 3001, Eckart GmbH) were presented in a laboratory kneader from IKA. In parallel, 3.5 g of epoxy group-containing compound (GE 100, Fa. Raschig,

Epoxidqäuivalentgewicht 140 to 170) dissolved in 60 g of ethanol having an H ₂ 0 content of 35 wt .-% and then mixed with the pigment in the kneader. After a mixing time of 20 minutes, the mixture was dried at 100.degree. The resulting surface-modified effect pigment with a

specific epoxide equivalent weight of 106,000 served as

Starting material for the subsequent powder coating applications.

Inventive Example 3:

150 g of commercially available weather-stabilized silver pearlescent pigment based on natural mica flakes (Phoenix XT 3001, Eckart GmbH) were presented in a laboratory kneader from IKA. In parallel, 4.1 g of epoxy group-containing compound (GE 500, Raschig, Epoxidäquivalientgewicht 160 to 180) were dissolved in 60 g of ethanol with an H 2 O content of 35 wt .-% and then mixed with the pigment in the kneader.

specific epoxide equivalent weight of 62000 served as starting material for subsequent powder coating applications.

Inventive Example 4:

150 g of commercially available stabilized aluminum pigment (standard aluminum powder PCU 3500, Eckart GmbH) were presented in a laboratory kneader from IKA. In parallel, 2.5 g of epoxy group-containing compound (Cyracure 6105, Dow Corning, Epoxidäquivientgewicht 130 to 135) in 60 g of ethanol having an H ₂ 0 content of 8 wt .-% dissolved and then mixed with the pigment in the kneader.

After a mixing time of 20 minutes, the mixture was dried at 100.degree. The resulting surface-modified effect pigment with a

specific epoxide equivalent weight of 9200 served as starting material for subsequent powder lacquer applications. Inventive Example 5:

100 g of commercially available, silver pearlescent pigment based on ΤΊΟ2 coated mica platelets of fineness 5-25 μητι (PHOENIX PX 2001, Eckart GmbH) were suspended in 300 ml of isopropanol and on

Boiling temperature brought. With stirring, initially 2.0 g of H ₂ O and then within one hour a solution of 2.17 g of Ce (NO ₃ ) ₃ in 100 g of isopropanol was added. Subsequently, a solution of 0.45 g

Added ethylenediamine in 3.0 g H ₂ O. Then, over a period of 2 hours, 10.6 g of tetraethoxysilane and 22 g of isopropanol were introduced continuously by means of a metering pump. Then the suspension was allowed to react for a further 6 hours. The mixture was added overnight

Stirred room temperature and filtered the next day through a Buchner funnel.

The pigment filter cake was submitted in a laboratory kneader Fa. IKA. In parallel, 2.5 g of epoxy group-containing compound (Cyracure 6107, Dow Corning, epoxide equivalent weight 131 to 140) in 30 g

Isopropanol dissolved with an H ₂ O content of 10 wt .-% and then mixed with the pigment in the kneader.

specific epoxy equivalent weight of 20000 served as starting material for the subsequent powder coating applications.

The following comparative examples mention the effect pigments to be used in a powder coating.

Comparative Example 1

Phoenix XT 3001 (Eckart GmbH): commercially available weather-stabilized silver pearlescent pigment based on natural

Mica flakes. Comparative Example 2:

Phoenix PX 3001 (Eckart GmbH): commercially available silver pearlescent pigment based on natural mica flakes.

Comparative Example 3

100 g of commercially available, silver pearlite pigment based on TiO ₂ coated mica platelets of fineness 1-15 μm (PHOENIX PX 3001, Eckart GmbH) were suspended in 300 ml of isopropanol and brought to the boiling point. With stirring, initially 2.0 g of H ₂ O and then within one hour a solution of 2.17 g of Ce (NO ₃ ) ₃ in 100 g of isopropanol was added. Subsequently, a solution of 0.45 g of ethylenediamine in 3.0 g of H2O was added. Then, over a period of 2 hours, 10.6 g of tetraethoxysilane and 22 g of isopropanol were introduced continuously by means of a metering pump. Then the suspension was allowed to react for a further 6 hours. The mixture was stirred overnight at room temperature and filtered the next day through a Buchner funnel.

The pigment filter cake was dried at 120 ° C in a vacuum oven.

The resulting effect pigment served as a comparison material for the subsequent powder paint applications.

Comparative Example 4

100 g of commercially available, silver pearlescent pigment based on TiO ₂ coated mica platelets of fineness 1-15 μm (PHOENIX PX 3001, Eckart GmbH) were suspended in 300 ml of isopropanol and dissolved

Boiling temperature brought. With stirring, initially 2.0 g of H ₂ O and then within one hour a solution of 2.17 g of Ce (NO ₃ ) 3 in 100 g of isopropanol was added. Subsequently, a solution of 0.45 g of ethylenediamine in 3.0 g of H ₂ O was added. After that, you conducted over a period of time of 2 h 10.6 g of tetraethoxysilane and 22 g of isopropanol by means of a metering pump continuously. Then the suspension was allowed to react for a further 6 hours. 2.0 g of 3- (2,3-epoxypropoxy) propyltrimethoxysilane (Dynasylan GLY O, Evonik) were then added and the mixture was allowed to cool slowly. The mixture was stirred overnight at room temperature and filtered the next day through a Buchner funnel.

The pigment filter cake was dried at 120 ° C in a vacuum oven.

The resulting surface-modified effect pigment served as

Comparative material for the subsequent powder coating applications.

Comparative Example 5:

Standard aluminum powder PCU 3500 (Eckart GmbH): commercially available stabilized aluminum pigment.

Comparative Example 6:

The starting material is standard aluminum powder PCU 3500, a commercial! available stabilized aluminum pigment used (Eckart GmbH), wherein according to Example 1 of WO 2005/063897 A2, the further layer mitteis spray-drying was applied. However, instead of the standard aluminum powder PCR 501 used there, the type standard aluminum powder PCU 3500 was used.

II. Application behavior of the powder coatings

The respective effect pigment was combined with the highly weather-resistant powder coating 059/82170 black (Tiger) and 0.2% Acematt OK 412 (Evonik) with ThermoMix for 4 minutes at level 4 incorporated. The pigmentation level was 5.0 wt .-%, since in this pigmentation verifiable application behavior is achievable

As a result, the powder paint was weighed out to 95.0% by weight. The

Total amount of powder paint in the mixer was 300 g plus 0.6 g Acematt OK 412.

The ThermoMix is a commercial kitchen mixer (Vorwerk). The additive Acematt OK 412 is SiO ₂ particles having a mean agglomerate particle size of 6.0 μm, which in this application assumes the function of a pouring agent. The Puiver! Acke were with the powder coating gun OptiSelect (ITWGema) in a commercial

Coating booth applied. To judge the

Application properties were sprayed into the coating booth for 20 seconds according to the parameters given in Table 1, then the coating of the substrate was carried out and then the adhesions at the electrodes and at the baffle plate were assessed comparatively. This method allows a conclusion on the long-term behavior of the effect pigments during a practice-oriented coating.

Furthermore, based on the baked Pulveriackierung the

Surface image rated. The focus was mainly on the course, so the smoothness of the surface structure, as well as on black, microscopic missing parts, so-called black spots thrown. Black spots are areas on the powder coating surface that are caused by an inhomogeneous distribution of the effect pigments. Since these phenomena are in the macroscopic range, a lacquer-technically trained look is needed to assess the appearance. In particular, very smooth structures with a very smooth course without the appearance of black spots are preferred.

The application behavior, the presence of black spots and the structure or the course of the powder coatings were assessed visually. Table 1

Example 40 kV-10 μΑ / 2.5 Nm3 / h-70% 100 kV-100 μΑ / 2.5 Nm3 / h-70% or pre-application runner Application Black Application Black

Structure / History / History Example behavior Spots Str

behave spots

very uniform

Req. gem. very uniform low

A no no

Structure/

Buildup no

Example 1 Structure /

adhesions

slight waviness slight waviness

Comparative mean inconsistent structure / none

A uneven structure / example 1 attachments yes orange peel buildup yes orange peel

Req. gem. very uniform

medium very uniform none

B no structure /

Example 2 buildup no structure /

adhesions

slight waviness slight waviness inconsistent structure / heterogeneous structure /

Comparative mean

B no

Step Example! 2 orange skin,

Buildup yes buildup yes orange peel, pigment pigment agglomerate

Req. gem. no single structure / single structure / none

C no

Example 5 adhesions no ripple

Ripple buildup

extremely uneven extremely uneven

Comparative mean structure /

none

C structure /

example 3 buildup yes buildup yes orange peel, bad

Orange peel, matte edge finish more even

Req. gem. low uniformity / low

D no structure /

Example 4 no

Buildup slight waviness

adhesions

slight waviness

Comparative heterogeneous structure / heterogeneous structure /

D medium

Example 5 buildup yes a orange peel

Orange-skin adhesions j

No comparison none

Example 6 No

Adhesions optical depth effect no

Adhesions optical depth effect

At an application voltage of 40 kV-10 μΑ showed powder coatings containing effect pigments from the comparative examples significantly stronger adhesion to baffle plate and electrode than powder coatings containing surface-modified effect pigments according to the examples of the invention. In powder coatings, soft effect pigments according to the

Comparative examples contained clearly black spots were to be recognized after the application, whereas in powder coatings, which

contained surface-modified effect pigments from the examples of the invention, not or only to a very limited extent was the case. Furthermore, the course of the powder coating and the structure of the appearance was positively influenced by the surface-modified effect pigments according to the inventive examples. Both the course and the structure were perceived much more uniformly by the viewer.

The improved optical properties in the direct comparison of applications obtained with powder coatings comprising surface-modified effect pigments according to the examples according to the invention, with applications comprising powder coatings containing the corresponding non-surface-modified effect pigments, were particularly evident

Expression. In Table 1, therefore, the respective letter in the column "precursor" refers to the same starting material, which was then surface-modified according to the inventive examples or used according to the comparative examples.

At an application voltage of 100 kV-100 μΑ almost all tested powder coatings showed good to very good application properties.

However, the appearance of the baked powder paint on the sheet was very different.

Powder coatings which contained surface-modified effect pigments according to the examples according to the invention had, compared with the corresponding powder paints with effect pigments For example, a significantly more uniform structure and a smoother course of the pigmented powder coating can be seen.

Again, black spots were only in the applications of powder coatings, soft effect pigments contained according to the Vergieichsbeispielen recognize. In applications of powder coatings containing surface-modified effect pigments according to the examples of the invention, these did not occur.

Comparative Example 6 was an effect pigment prepared according to WO 2005/063897 A2. Effect pigments prepared in this way can be applied very well in a powder paint application because of comparable electrostatic properties of the powder coating particles and the effect pigments coated with the corresponding binder. In contrast to powder application which contain the effect pigments to be used according to the invention, these powder coating applications are distinguished by their optical depth effect. An observer perceives a certain glittering effect over the entire viewing angle. A powder coating containing effect pigments according to Comparative Example 6 therefore has an overall more lively effect than the powder coating containing a uniform appearance containing the invention

to be used surface-modified effect pigments.

This difference can also be detected by light microscopic images. Figure 1 shows a light micrograph (light microscope Axio Imager Z1m, Zeiss) of the effect pigment of Comparative Example 5. Figure 2 shows a

corresponding photomicrograph of the effect pigment from Comparative Example 6. In Figure 1, unlike Figure 2, the effect pigments are arranged largely plane-parallel to the substrate. This is perceived by the human eye as a homogeneous appearance when considering the corresponding Puiverlackapplikation. Due to the rather statistical distribution of the effect pigments in Figure 2 the corresponding powder coating application is seen by the human eye as alive and with depth effect.

Ml. Facades cleaning test

To assess the facade cleaning ability, a paint panel coated with the correspondingly pigmented powder coating was indicated for resistance to abrasion by detergents

examined.

To carry out a square tube (L = 12 cm / W = 6 cm / H = 4

cm / weight 500 g) once wrapped with a soft cloth.

Sequence: 2 m! The cleaning solution Ambruch 2 Plastic Intensive Cleaner (Rudolf Ambruch GmbH) was evenly distributed on the cloth. The paint panel with the coating to be tested was fixed on a table and the square pipe moved back and forth on the coated paint panel without exerting any additional weight. Here once "back and forth" corresponds to one cycle.

After every 10 cycles, the detergent was removed with a dry cloth. Subsequently, the sequence described above was repeated twice until a total of 30 cycles were reached.

To assess the paint panels were visually inspected for a color and / or effect shift.

Table 2

Powder coatings containing effect pigments from Comparative Examples 1, 3 and 4 had a medium to strong loss of effect. On the corresponding paint panels a very clear discoloration in the direction of black (color of the powder coating used) was observed. These paint panels looked extremely uneven and visually very unattractive after the test.

Powder coatings containing surface-modified effect pigments according to the examples according to the invention also had an effect loss. This was less pronounced. There was only a slight discoloration towards black. The desired gloss effect (generated by the respective surface-modified

Effect pigment) remained almost intact. The corresponding paint panels appeared much more uniform to the viewer. A possible explanation for this could be that the

Surface-modified effect pigments due to the additional

Epoxidgruppen much better with the surrounding powder coating änterieren and form covalent bonds. The surface-modified effect pigments are thus better integrated into the powder coating matrix, which manifests itself in improved cleanability,

IV. Determination of Specific Epoxy Equivalent Weight of

surface-modified effect pigments

The specific epoxide equivalent weight is understood to mean the amount of pigment in grams which contains 16 grams of epoxide oxygen (epoxide oxygen). The determination of the specific epoxide equivalent weight was carried out as follows:

10.0 g of surface-modified effect pigment was weighed into an 80 ml beaker and concentrated in about 10 ml of chloroform and about 40 ml of conc. Stirred up acetic acid. Approximately 2.5 g of cetyltrimethylammonium bromide were added and dissolved with stirring, if appropriate also heating. The sample was agitated on a magnetic stirrer and a pH electrode was immersed. The sample was titrated with 0.1 N acetic perchloric acid. The consumption thus determined is included as VB (1) in the calculation of the specific epoxide equivalent weight.

Since different occupied effect pigments could enter into a neutralization reaction with the perchloric acid even without epoxide coating, it is necessary to use a so-called Nuli value or also called Aminzahi, to determine the respective starting pigments. The consumption VB (2) of Titrand to determine the zero value is then determined by the

Consumption VB (1) deducted to determine the epoxide content. To determine the Nuilwertes or amine number, 10.0 g not surface-modified effect pigment were weighed into a 80 ml beaker and in about 10 ml of chloroform and about 40 ml conc. Stirred up acetic acid. The sample was placed on a magnetic stirrer and immersed in a pH electrode. The sample was titrated with 0.1 N acetic perchloric acid. The consumption thus obtained is included as VB (2) in the calculation of the specific epoxide equivalent weight.

The weight in grams of the respective effect pigment depends on the expected specific epoxide equivalent weight and is equal to the determination of the zero value. The respective weight can

are taken from Table 3 below.

Table 3

Evaluation:

Specific epoxide equivalent weight - weight (g) -1000

(VB (1) [ml] - VB (2) [ml]) - n - f

N = normality of the titrant

f = factor of the titrant V. Determination of the epoxide equivalent weight of the epoxide group-containing compound

By epoxide equivalent weight is meant the amount of pigment in grams which contains 16 grams of epoxide oxygen (epoxide oxygen). The determination of the epoxide equivalent weight was carried out as follows:

Depending on the expected epoxide equivalent weight, the amounts of epoxide group-containing compound were weighed into a 80 ml beaker according to Table 3 and concentrated in about 10 ml of chloroform and about 40 mi. Acetic acid dissolved. Approximately 2.5 g of cetyltrimethylammonium bromide were added and dissolved with stirring, if appropriate also heating. The sample was placed on a magnetic stirrer and immersed in a pH electrode. The sample was titrated with 0.1 N acetic perchloric acid.

Evaluation:

Epoxide equivalent weight = ^Einwaa S ^e (g) ^^

(VB [ml] - n - j)

N = normality of the titrant

f = factor of the titrant

VI. Particle size

The size distribution curve of the effect pigments based on

nonmetallic piättchenförmigen substrates was determined using a device from. Maivern (device: MALVERN Mastersizer 2000) according to the manufacturer. For this purpose, about 0.1 g of the corresponding effect pigment as an aqueous suspension, without the addition of dispersing aid, with constant stirring by means of a Pasteur pipette in the sample preparation cell of the measuring device and measured several times. From the individual measurement results, the resulting averages were formed. The evaluation of the scattered light signals was carried out according to the Fraunhofer method.

The size distribution curve of the effect pigments based on metallic platelet-shaped substrates was measured with a Quantachrome device (device: Cilas 1064) according to the manufacturer's instructions. For this purpose, about 50 ml of the respective pigment were suspended in isopropanol, 300

In the ultrasonic bath (device: Sonorex IK 52, from Bandelin) and then added to the sample preparation cell of the measuring device by means of a Pasteur pipette and measured several times. From the individual measurement results, the resulting averages were formed. The evaluation of the scattered light signals was carried out according to the Fraunhofer method.

In the context of this invention, the average diameter D50 is the Dso value of the cumulative frequency distribution of the volume components

Size distribution function, as obtained by laser diffraction methods understood. The D ₅ o value indicates that 50% of the effect pigments have a diameter which is equal to or less than the stated value, for example 20 μm. Accordingly, the Dgo value indicates that 90% of the effect pigments have a diameter equal to or less than the respective value. Furthermore, the Di ₀ value indicates that 10% of the effect pigments have a diameter equal to or less than the respective values.

Claims

claims

1. Use of surface-modified effect pigments in one

solvent-free coating agent,

characterized,

in that the surface-modified effect pigments have a platelet-shaped substrate and at least one dielectric layer, wherein at least one optional layer is present on the at least one dielectric layer

Protective layer may be arranged, and the effect pigments on the

Effect pigment surface are surface-modified with at least one epoxide group-containing compound, with the proviso that the at least one epoxide group-containing compound contains no Siüziumatome.

2. Use according to claim 1,

characterized,

the platelet-shaped substrate is a non-metallic platelet-shaped substrate and is preferably selected from the group consisting of natural mica platelets, synthetic mica platelets, glass flakes, S1O2 platelets, Ai203 platelets and mixtures thereof.

3. Use according to claim 1,

characterized, that the platelet-shaped substrate is a metallic substrate and the metal of the metallic substrate is preferably selected from the group consisting of aluminum, copper, zinc, iron, stainless steel, their

Alloys and mixtures thereof is selected.

4. Use according to one of the preceding claims,

characterized,

in that the at least one dielectric layer is selected from the group consisting of metal oxides, metal oxide hydrates, metal hydroxides, organic dielectric materials and mixtures thereof.

5. Use according to one of the preceding claims,

characterized,

in that the at least one optional protective layer comprises the metal oxides, metal oxide hydrates and / or metal hydroxides of aluminum, cerium, chromium, silicon, zirconium and / or mixtures thereof.

6. Use according to one of the preceding claims,

characterized,

the at least one optional protective layer is metal oxides,

Metailoxidhydrate and / or metal hydroxides of silicon and / or acrylates and / or mixtures thereof.

7. Use according to one of the preceding claims,

characterized,

the at least one epoxide group-containing compound has at least two epoxide groups.

8. Use according to one of the preceding claims,

characterized,

the proportion of the at least one epoxide group-containing compound is in a range from 0.5 to 8% by weight, based on the total weight of the surface-modified effect pigment.

9. Use according to one of the preceding claims,

characterized,

that the surface-modified effect pigments have a middle

Have diameter D ₅₀ from a range of 2 to 100 μηι.

10. Use according to one of the preceding claims,

characterized,

that the surface-modified effect pigments have a specific

Epoxy equivalent weight from a range of 119000 to 800, based on the total weight of the oberfiächenmodifizierten effect pigment having.

11. Use according to one of the preceding claims,

characterized,

that the loose iterless coating agent is a powder coating or toner.

12. Surface-modified effect pigments comprising piättchenförmige

Substrates having at least one dielectric layer, wherein on the at least one dielectric layer at least one optional

Protective layer can be arranged

characterized,

in that the effect pigments on the effect pigment surface are surface-modified with at least one epoxide group-containing compound, with the proviso that the at least one epoxide group-containing compound contains no silicon atoms, and the surface-modified effect pigments have a specific epoxide equivalent weight in the range from 119,000 to 800, based on the total weight of the surface-modified

Effect pigments.

13. Solvent-free coating agent containing surface-modified

Effect pigments,

characterized,

the surface-modified effect pigments are platelet-shaped Substrate and at least one dielectric layer, wherein on the at least one dielectric layer at least one optional

Protective layer may be arranged, and the effect pigments on the

Effect pigment surface are surface-modified with at least one epoxide group-containing compound, with the proviso that the at least one epoxide group-containing compound contains no silicon atoms.

14. Solvent-free coating composition according to claim 13,

characterized,

that the surface-modified effect pigments are a specific

Epoxy equivalent weight from a range of 119,000 to 800, based on the total weight of the surface-modified effect pigments.

15. Solvent-free coating composition according to claim 13 or 14,

characterized,

the solvent-free coating agent is a powder coating or a toner.

16. Coated article,

characterized,

the article is coated with a solvent-free coating composition according to any one of claims 13 to 15.